DescriptionHealthcare providers are now required to provide their patients access to their progress notes. Early research of this concept, known as OpenNotes, showed promising results in term of provider acceptability and patient adoption. The aim of this pilot work is to assess the effect of the complexity level of provider’s notes on the user’s perceived usability, cognitive workload. Performance and satisfaction with the information included in the notes. We used a mixed method approach where participants were randomly assigned to one of the two conditions, complex vs. simple notes. The participants read the notes and answered questions about their perceived usability, cognitive workload and satisfaction, including few open-ended questions. Our analysis showed no statistically significant effect of the note’s complexity on the dependent variables. The overall perceived usability, cognitive workload, and satisfaction scores were considered low, indicating the design of the notes needs improvement. We conducted a content analysis on the interview answers to identify improvement recommendations for the notes.